I've recently been approached by a Salafi who believes that following a madhhab in the
manner of salat is bid'a, He differentiates the following of a madhhab's conditions
for salat from the sunnah of the Nabi (saw)

Answer:

Usually Salafis are not aware of the requirements and conditions of Prayer. And they
pass judgement on others who do not pray just as they do. They often contradict themselves
in order to convince themselves that following a Madhhab is a reprehensible innovation.

At the same time when they read a classical Islamic text, most likely its author is one
who follows a madhhab. They cannot get over the fact that Imam Bukhari was Shafi`i not to
mention the author of the book they love to read from after salat, Riyaadhus-Saaliheen--Imam
Nawawi was Shafi`i. The list here is to long to write. 95% of these books are by scholars
from the Ahl as-Sunnah wal Jama`ah--those who followed the Madhhabs Maliki,
Shafi`i, Hanbali and Hanafi (Ridhwaanu-Llahu `Alaihim). And to leave the Jama`ah,
is to leave the Party of Allah and His Prophet (saw).

What the Scholars said about the Jama`at

Shaykh al-Islam Ahmad ibn Hajar al-Haytami (d. 974/1567; R. A.)

Hafiz Ibn Hajar al-Haytami defined the Sunni Muslims as follows in his book Fath
al-jawad: "A Mubtadi (innovator) is the person who does not have the faith (Aqeedah)
conveyed unanimously by the Ahl as-Sunnah. This unanimity was transmitted by the
two great Imam's Abu'l Hasan al-Ashari (d.324/936; Rahimahullah) and Abu Mansur al-
Maturidi (d.333/944; Rahimahullah) and the scholars who followed their path."
Hafiz Ibn Hajar al-Haytami also said in his book al- Fatawa al-Hadithiyya (pg. 205):
"'Man of bid'ah' means one whose beliefs are different from the Ahl
as-Sunnah faith. The Ahl as- Sunnah faith, is the faith of Abu'l Hasan
al-Ashari, Abu Mansur al- Maturidi and those who followed them. One who brings forth
something which is not approved by Islam becomes a man of bid'ah."

Contrary to our belief, when Allah says, "And hold fast, all of you together,
to the rope of Allah and be not divided." the Salafis take this as to mean that
it is the Madhhabs that cause the division. But as usual, their understanding of Allah`s
words has no depth and they lack comprehension of this matter and many others.

Imam Qurtubi

Of this verse Qurtubi says:
'Be not divided in your religion as were the Jews and Christians divided in their
religions' and 'Be not divided in following different false opinions and purposes. Rather,
be brothers in God's religion.' As a jurist, Qurtubi observes that, 'There is no
indication in this verse of the prohibition of disagreement in the branches (furu')
[of fiqh] as this in reality not dissension. This is because true dissension is one
wherein concord and unity become virtually impossible. `

Below I will cite the narrations of the Imams of hadith regarding the Saved Sect (firqatunnaajiyya) and the importance of holding to the majority group (Jama`ah).

Imam Abu Dawood

Imam Abu Dawood (Rahimahullah) concerning the division of the Muslim Ummah into
seventy- three sects in his Sunan (3/4580, English edn) said:
Abu Amir al- Hawdhani said, "Mu'awiyah ibn Abi Sufyan (may Allah be pleased with him)
stood among us and said, 'Beware! The Apostle of Allah (may peace be upon him) stood among
us and said': 'Beware! The People of the Book before (you) were split up into 72 sects,
and this community will be split up into 73, seventy-two of them will go to Hell and one
of them will go to Paradise, and it is the majority group (Jama'ah).'

Hafiz Ibn Kathir

Hafiz Ibn Kathir (Rahimahullah) in The Signs Before The Day of Judgement
(pg. 14):

"Awf ibn Malik reported that the Prophet (Peace be upon him) said, 'The Jews split
into 71 sects: one will enter Paradise and 70 will enter Hell. The Christians split into
72 sects: 71 will enter Hell and one will enter Paradise. By Him in Whose hand is my soul,
my Ummah will split into 73 sects: one will enter Paradise and 72 will enter Hell.'
Someone asked, 'O Messenger of Allah (Peace be upon him), who will they be?' He replied,
'The main body of the Muslims (al-Jama'ah).'

Ibn Taymiyya

Even Ibn Taymiyya, the leader of Salafi though, in his Aqeedat-il-Wasitiyyah
(pg. 154) says: "Their creed is the religion of Islam which was sent to the world by
Allah through the Prophet (Peace be upon him). But the Prophet (Peace be upon him) said,
'My Ummah will get divided into 73 sects and each one will go to Hell save one and that
one is the Jama'at.' Also in one Hadith he said, 'They are those people who will
follow this path which I and my Sahaba follow today.' Therefore they have caught hold of
Islam unalloyed from every adulteration and these are the people of Ahl as-Sunnah Wa'l
Jama'ah. This group includes the truthful, the martyrs and the virtuous; it includes
the minarets of guidance, lamps in the darkness and owners of such superiorities and
virtues who have been already mentioned. It includes thesaints and also those
Imams on whose guidance Muslims are unanimous. It is this successful group about which
the Prophet (Peace be upon him) has said: 'One group from my Ummah will always remain
dominant with truth; the opponents will never be able to harm its members or afflict them
up to the Doomsday.'"

Imam Muslim

Imam Muslim (Rahimahullah) has collected a number of variant Hadith on the saved
sect. He has related a longer version of the last Hadith quoted above: "Abdal Rahman
ibn Shamasa al-Mahri said: 'I was in the company of Maslama bin Mukhallad and Abdullah ibn
Amr ibn al-Aas (may Allah be pleased with them).' Abdullah said, 'The Hour shall come only
when the worst type of people are left on the earth. They will be worse than the people of
pre-Islamic days. They will get whatever they ask of Allah.' While we were sitting Uqba
ibn Amir came, and Maslama said to him, 'Uqba, listen to what Abdullah says.' Uqba said,
'He knows, so far as I am concerned, I heard the Prophet (Peace be upon him) say: A group
of people from my Ummah will continue to fight in obedience to the Command of Allah,
remaining dominant over their enemies. Those who will oppose them shall not do them any
harm. They will remain in this condition until the Hour over takes them.' (At this)
Abdullah said, 'Yes. Then Allah will raise a wind which will be fragrant like musk and
whose touch will be like the touch of silk; (but) it will cause the death of all
(faithful) persons, not leaving behind a single person with an iota of faith in his heart.
Then only the worst of men will remain to be overwhelmed by the Hour.'" (Sahih
Muslim, 3/4721, English ed'n, see also Sahih al-Bukhari, 9/414, English ed'n)

Imam Nawawi

Imam Nawawi in his Sharh Muslim :
"The group of people (mentioned in the above Hadith) consists of scholars,
jurisprudents, authorities on Hadith, those who enjoin Good and forbid Evil and all such
persons who do good deeds. Such righteous persons may be found spread all over the
world."

Imam al-Tirmidhi

Imam al-Tirmidhi (Rahimahullah) said:
"The explanation of al- Jama'ah according to the people of knowledge: They are
the people of Fiqh, knowledge and Hadith." (Sunan al-Tirmidhi, 4/2167; Ahmad Shakir
ed'n).

Imam Bukhari

Imam Bukhari (Rahimahullah) stated in his Sahih:
"The statement of the Prophet (Peace be upon him): 'A group of my followers will
remain victorious in their struggle in the cause of the Truth.' Those are the
religious(ly) learned men (Ahl ul-Ilm)."

Imam Ahmad ibn Hanbal

Imam Ahmad ibn Hanbal (Rahimahullah) said about this group:
"If it is not the people of Hadith, then I do not know who they may be." (Sahih
Muslim Sharif-Mukhtasar Sharh Nawawi, vol. 5, pg. 183, W. Zaman ).

There are over fifteen hadiths mentioning this subject, but like before we will try to
limit this response. So in short, we can say there are differences in Furu`
(branches), but not in the Usul (fundamental principles), i.e. Quran and Sunnah.
For the Madhhabs may differ in some areas, but the efforts in `Ijtihad by their founding
Imams remain unequaled by anyone after the time of the Salaf, and thus cannot be tossed
out or replaced. And it is obligatory for the common folk to follow one of these Imams,
except the one that is a qualified Mujtahid.